I am having trouble using the programmer entry point interface to convert/parfrac. As an example consider : While
> convert([x, [I*(x+I), 1]], parfrac, x);
[-I, [(I + x) I, -I]]
correctly computes a partial fraction decomposition, the equivalent input
> convert([x, [I*x-1, 1]], parfrac, x);
results in the error message (both in Maple 16 and 17)
Error, (in convert/parfrac) denominator factors must be coprime
which does not make any sense to me, since there is only a single denominator factor present (and it is even the same factor as in the previous call, only written differently).
What is the reason for this behaviour and how can I use convert/parfrac in a way that avoids such errors?